The owners of Truth Aquatics and the dive boat Conception, Glen and Dana Fritzler, right, and their daughter Ashley, left, have filed a federal lawsuit to limit their liability.

Photo: KEYT-TV / Associated Press

Owners of the scuba diving boat that caught fire off the Santa Barbara County coast this week, killing 34 people, would be facing $100 million or more in potential liability to the victims’ families if the disaster had occurred on land.

It’s different at sea. Under an 1851 law invoked by boat owner Truth Aquatics Inc. and its principals in a federal lawsuit Thursday, owners who persuade a judge that they acted prudently in equipping and staffing a vessel and had no reason to suspect any dangerous conditions that led to the calamity would be on the hook for no more than relative pocket change — perhaps $30,000 in this case.

The Shipowners’ Limitation of Liability Act was enacted by Congress to protect the nation’s fledgling shipping industry. Owners of the Titanic used it to limit their payments to $92,000 for the deaths of more than 1,500 people after the ocean liner hit a North Atlantic iceberg in 1912. The U.S. Supreme Court described the law as outdated in 1954, and members of Congress have periodically sought, unsuccessfully, to repeal it.

“It’s arcane and shouldn’t be on the books,” said New York attorney Dan Rose, who represents plaintiffs in maritime and aviation law cases. Filing the suit in federal court three days after the lethal fire was “an insult on top of injury to these families,” he said.

On the other hand, said attorney Michael Karcher, who teaches admiralty law at the University of Miami, federal judges are aware of the law’s potential impact and hold shipowners to “a very high standard” to escape liability.

In other types of accidents, like a bus crash or a train wreck, employers are legally responsible for the misdeeds of their employees — a driver who took a wrong turn or ran through a stoplight, for example — even if they had no reason to foresee the misconduct. And the victims, or their families, can take their case to a jury in state court to determine fault and damages.

Under the 1851 law, once a ship’s owner sues in federal court, all potential cases are referred to that court. The owner then must prove — to a judge, rather than a jury — that the owner was not at fault, either by creating unsafe conditions or by failing to notice potential problems with the vessel or the crew.

As Truth Aquatics and its owners, Glen and Dana Fritzler, put it in their lawsuit in U.S. District Court in Los Angeles, “the fire and all consequential alleged injuries, damages and deaths ... (were) not caused or contributed to by any negligence, fault or knowledge on the part of (the owners), or anyone for whom (they) may be responsible.”

If U.S. District Judge Percy Anderson agrees, their damages would be limited to the current value of the sunken vessel — zero — or $420 for each ton of its weight, about $30,000. The victims could theoretically sue the boat’s captain or others they considered personally responsible, but that would generally be “completely pointless,” because those defendants would be unable to pay damages, said Martin Davies, a professor of maritime law at Tulane University.

If the owners fail to clear themselves, the judge must also decide whether the victims and their families have shown evidence of negligence, a decision that would also be left up to a jury in non-maritime cases. Anderson could then keep the case in federal court for a determination of damages, or allow the victims to sue in state court.

“Claimants would far rather be before a state jury than a federal judge,” Davies said. In addition, he said, the federal law allows the ship owner “to fight the case once rather than in 34 different courts,” with the possibility of “limiting their liability to next to nothing.”

Karcher said ship owners would have a harder time proving their case now than they did in the 19th century.

“In 1851, they didn’t have telephones or cell phones,” he said. “Nowadays, owners can look on their laptop and find out what the vessel is doing,” and can’t blithely claim ignorance of visible shipboard hazards.

Rose said most federal judges “are about as off-put about this law as you and I and the families are. They tend to give (victims) the benefit of the doubt.”

And he noted that another federal law, the Death on the High Seas Act, passed in 1920, allows victims’ family members to recover damages only for their economic losses, such as financial support and funeral costs, and not for other harms such as loss of care and companionship. It applies to deaths that occur at least 3 miles off U.S. shores, and not to Monday’s shipboard fire in a harbor off Santa Cruz Island.

Bob Egelko has been a reporter since June 1970. He spent 30 years with the Associated Press, covering news, politics and occasionally sports in Los Angeles, San Diego and Sacramento, and legal affairs in San Francisco from 1984 onward. He worked for the San Francisco Examiner for five months in 2000, then joined The Chronicle in November 2000.

His beat includes state and federal courts in California, the Supreme Court and the State Bar. He has a law degree from McGeorge School of Law in Sacramento and is a member of the bar. Coverage has included the passage of Proposition 13 in 1978, the appointment of Rose Bird to the state Supreme Court and her removal by the voters, the death penalty in California and the battles over gay rights and same-sex marriage.